Depth gauge attachment

ABSTRACT

A depth gauge attachment for use with a motorized grinder for sharpening a saw chain. The gauge is removably fixed to the grinder with the rotating grinding element thereof extending beyond the gauge. The grinder may then be adapted to grind the cutter gauge of a saw chain tooth whereby the cutter gauge portion of each cutter link of a saw chain may be sequentially ground to substantially the same clearance.

United States Patent Granberg Mar. 12, 1974 DEPTH GAUGE ATTACHMENT ElofGranberg, 201 Nevin Ave., San Rafael, Calif. 94801 Filed: July 17, 1972Appl. No.: 272,322

Inventor:

US. Cl 76/74, 76/25 A, 76/37 Int. Cl B23d 63/16 Field of Search 76/37,25 A, 74

References Cited UNITED STATES PATENTS ll/l967 8/1967 Kennemore.....

McLean 76/25 A Primary ExaminerLeonidas Vlachos Attorney, Agent, orFirmBruce & McCoy [5 7] ABSTRACT 8 Claims, 4 Drawing Figures DEPTH GAUGEATTACHMENT CROSS REFERENCE TO RELATED APPLICATIONS -This application isrelated to applicants copending U.S. Pat. application Ser. No. 156,859,filed June 25, 1971, for Grinding Apparatus and Method, now US. Pat. No.3,738,200.

BACKGROUND OF THE INVENTION 1. Field of the Invention This applicationrelates generally to rotary grinders for sharpening the cutter links ofa saw chain, and more particularly, to a depth gauge attachment for usewith a motorized sharpener whereby the cutter gauge of each saw chaintooth may be progressively ground to change the clearance of the cuttingportion of the tooth.

2. Description of the Prior Art Generally, each cutter link of a sawchain is provided with a cutter gauge at the front of the link and acutting portion at the rear end. Applicants copending US. Pat.Application Ser. No. 156,859, discloses a rotary grinder sharpeningmeans for sharpening the cutting portion of a cutter link of a sawchain.

As a chain saw is usedQthe cutter links lose their sharpness and weardown. In addition, when the same chain saw is used for cutting differenttypes of wood, the bite or amount of wood taken on each cut of the chainsaw may vary considerably, depending on the hardness of the wood beingcut. Therefore, in presently available saw chains, the cutter gaugeportion of the link is machined to a predetermined height to control thebite or amount of wood taken by each pass of a cutter link. To modifythis cutter gauge for use with different hardness of woods, or to takeinto account the wearing of the cutting portion of the tooth, the cuttergauge portion is normally filed by hand. Accuracy in filing each cuttergauge by hand is rarely, if ever achieved. As a result, there exists aneed for a means for accurately taking the same amount of material offeach cutter gauge portion of the links of a saw. chain. Such a meanswill decrease the overall wear of the saw chain by insuring that eachlink takes the same cut or bite during each pass through the wood beingsawed.

The present invention provides a cutter gauge attachment for use with amotor driven saw chain sharpening means which permits the saw chainsharpening means to grind or remove the same amount of material fromeach cutter gauge of the separate cutter links of a saw chain.

SUMMARY OF THE INVENTION A depth gauge attachment for a saw chainsharpener having a grinding element. The attachment comprises a platecapable of being removably secured to a sharpener over the grindingelement. The plate includes a flat portion having an opening formedtherein through which a portion of the grinding element extends wherebywhen the grinder is placed on a chain saw bridging a pair of adjacentlinks, the plate may be adjusted with respect to the sharpener to enablethe depth gauge of the cutting link over which the grinding element isheld to be ground to a predetermined height.

OBJECTS OF THE INVENTION It is therefore an important object of theinvention to provide a depth gauge attachment which may be removablysecured to a motorized grinder for grinding the cutter gauge of a cutterlink of a saw chain.

It is a further object of the present invention to provide a depth gaugeattachment for a grinder which may be adjusted with respect to thegrinder to permit varying the amount the depth gauge is machined.

It is another object of the instant invention to provide a taperedportion on a depth gauge attachment for a grinder for causing thegrinding element to be moved longitudinally across the top of a cuttergauge when the tapered edge is held against a fixed surface while thegrinder is moved laterally across the cutter gauge.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a bottom plan view of a portion ofthe frame of a motorized grinder for sharpening a saw chain having thedepth gauge attachment of the present invention secured thereto;

FIG. 2 is a cross sectional view showing the depth gauge attachmentbridging two adjacent cutter links in a saw chain with the grindingelement over the cutter or depth gauge of a cutter link to be ground;

FIG. 3 is a top elevational view of the depth gauge of the presentinvention; and

FIG. 4 is a side elevational view of the depth gauge of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention is a depthgauge attachment for use with a saw chain grinder of the type disclosedin applicants copending US. application Ser. No. 156,859. With the depthgauge of the present invention attached to the frame of the saw chainsharpener of application Ser. No. 156,859, the grinding element thereofmay be used to sequentially grind the cutter gauge of each cutter linkto a predetermined height.

Turning now to the drawings, FIG. 1 shows a preferred embodiment of adepth gauge attachment 11 of the instant invention removably secured toa frame 13 of a sharpener. Frame 13 is preferably a unitary elementhaving an electrical motor (not shown) nested within an open centralportion thereof.

A cross member 15 having indicating means for aligning or holding thegrinder at the proper sharpening angle with respect to a saw chaincutting link or tooth is provided within the frame 13. This cross memberincludes a pair of side braces 17 having a pair of web plates 19, 21fixed therebetween. The plates preferably stop short of a centralportion of the cross member to provide an opening 23 between the ends ofthe web plates.

One of the plates, preferrably plate 19, includes a pair of holes 25which may be bottomed within the plate or pass completely therethrough.These holes also pass through an adjustment plate means 27 fixed to theframe for pivotal movement with respect thereto.

If the frame 13 is formed with only one side plate, the attachment 11may be provided with a stud 20 (shown in phantom line in FIGS. 2, 3 and4) on the appropriate side thereof which is secured to the plate in anyconvenient manner such as be welding. This stud is preferably threadedand passes through an opening (not shown) formed in the frame plate andincludes a fastening means, such as a nut, for securing the gauge to theframe. The depth gauge attachment may be made adjustable with respect tothe frame of the grinder to allow the positions of the attachment to beadjusted with respect to the grinding element 31 of the saw chainsharpener.

The electrical motor nested within the frame 13 includes a drive shaft29 extending outwardly therefrom toward the cross member 15. The driveshaft preferably includes a removable hollow insert, described moreclearly in applicants copending application, having a threaded innerportion into which the threaded end of the grinding element 31 may beengaged.

As shown, the grinding element extends outwardly over the space 23between the plates 19, 21 and into an opening 33 formed within the depthgauge attachment 11. The depth gauge attachment is secured to the bottomportion of the frame 13 by catching or hooking one end 35 of the depthgauge over a ridge 37 formed on the side of the frame. Ears or tabs 39formed on the opposite end of the depth gauge attachment are then linedup with the holes 25 in the cross members and rotated into the same tofirmly seat or snap the gauge into position on the frame.

The preferred embodiment of the depth gauge attachment comprises a flatbottom or plate portion 41, made from a stiff material, such as a metalor the like. The plate portion is preferably a four sided elongatedplate having two ends 35, 43 and two long sides 45, 47. As shown, one ofthe short sides, namely 35, angularly extends between the long sides.This angled side is formed with a folded-over endportion 49 for hookingonto or over the ridge 37 on the grinder frame. The folded-over endportion 49 extends away from the upturned edge portion so as to restsubstantially parallel to the flat plate 41. The inner edge 51 of thisfolded over portion is preferably formed so as to extend sub stantiallyparallel to the other short side 43.

The other or second short side 43 of the plate is square and alsoincludes an upturned edge portion extending in the same direction andapproximately onehalf the height of the upturned edge portion on thefirst short side 35. This upturned edge portion includes the pair oftabs 39 which extend upwardly therefrom, for substantially the samedistance as the upturned edge portion of side 35.

When the flat inner edge 51 is placed over the ridge 37 formed on theframe 13, and the plate rotated, the ears or tabs 39, extending from theupturned edge of the other short side 43 will be moved into the holes25, to enable the depth gauge attachment to be held firmly in position.

The opening 33 is formed in the flat plate portion 41 of the attachmentat a predetermined position whereby when the plate is mounted on theframe, the opening will be aligned with the grinding bit 31. In thisposition, an adjustment screw 53 may be turned to adjust the pivotingplate 27 to thereby adjust the depth gauge attachement with respect tothe frame of the grinder. This adjustment of the gauge will vary theamount the grinding element extends beyond or through the opening 33.

The long sides 45, 47 of the plate are also provided with upturned edgeportions, extending outwardly in the same direction for substantiallythe same distance as the upturned edge portion of the side 43. Theopening 33 is provided with a down turned guard portion 55, extendingsubstantially perpendicular thereto in the direction opposite to theupturned edge portions of the plate. The guard portion 55 acts to guardthe cutting portion of a cutter link when the grinder having the depthgauge attachment fixed thereto is placed on a saw chain bridging twocutter links.

As shown most clearly in FIG. 2, with the depth gauge attachment mountedon the grinder and resting or bridging two cutter links 57 of a sawchain, the bottom of the plate 41 is brought to rest against the top ofthe two alternating links with the tooth guard 55 extending into a linkbetween the grinding element and a cutter edge 59 on the link and thedepth gauge 61 thereof. The screw 53 of the plate is then adjusteddownwardly so that the pivotable plate 27 presses against the depthgauge attachment until the bottom of the gauge attachment issubstantially flush with the outer portion of the grinding element.

The screw 53 is then backed off, a given number of turns, depending onthe pitch of the screw thread, and the size of the adjustment plate. Ina preferred embodiment of applicants invention, the screw is providedwith a hexagonal head having sides which are 0.005 foot wide. The pitchand the contact point with the adjustable plate are such that onecomplete turn of the screw, in a backed-off direction, will expose thegrinding wheel 0.030 inch. In this manner, if it is desired to exposemore of the grinding element, each 1/6 of a turn of the screw will addan additional 0.005 inch.

When the desired adjustment is made, the grinding wheel is placeddirectly over one of the cutter gauges 61. The saw chain is then grippedwith one of the hands of the user, and the tapered end portion 35 of theattachment is placed against one of the fingers, such as the thumb, ofthe users other hand. The grinder is then started and moved laterally orperpendicularly (direction AA) to the chain back and forth over the sawchain. The tapered or angled portion of side 35 resting against thefinger of the user will provide a slight longitudinal (direction BB)motion to the grinder. In this manner, the entire top area of the cutterdepth gauge may be ground off to the adjusted height. The entire grinderis then moved to a further tooth so as to sequentially or successivelygrind all of the cutter gauges of a saw chain to the desired clearancedepth.

It therefore can be seen that an important feature of the presentinvention is the provision of a depth gauge attachment which may beeasily attached to or removed from presently available saw chainsharpeners. The grinder may then be used to sequentially grind all thecutter gauges to a predetermined set clearance to provide more uniformcutting performance by each of the saw chain teeth.

Obviously, many modifications and variations of the present inventionare possible in light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims, the inventionmay be practiced other than as specially described.

I claim:

1. A depth gauge attachment for use with a motorized saw chain sharpenerhaving a grinding element for machining the cutter gauge of a saw chainlink, the attachment comprising:

a plate removably secured to said sharpener and including a flat portionhaving an opening formed therein through 'which a portion of thegrinding element extends,

a guard formed by a portion extending substantially perpendicularly fromsaid plate adjacent said opening, whereby, when said flat portion ofsaid plate is placed on a saw chain bridging two links, said grindingelement will engage the top surface of the cutter gauge of one of saidlinks to a predetermined depth and said guard will extend into anopening in said link between said grinding element and the cutting edgeof the link being ground to prevent the grinding element from hittingsaid cutting edge.

2. The depth gauge attachment of claim 1 wherein said plate isadjustable with respect to said saw chain sharpener to change the amountof grinding element which extends through said opening.

3. The depth gauge attachment of claim 2 wherein said plate includes astud fixed to one side thereof for securing said attachment to thesharpener, and said saw chain sharpener includes adjustable means tochange the amountof grinding element which extends through said opening.

4. The depth gauge attachment of claim 2 wherein said saw chainsharpener includes a frame having a cross member bracketing the sidesand end of the grinding element and forming an opening through which thegrinding element extends and over which said plate is mounted, saidplate including upturned edge portions extending in the directionopposite from said plate than said guard portion and engaging said crossmember in such a manner that said attachment is spaced a predetermineddistance from said cross member.

5. A depth gauge attachment for use with a motorized saw chain sharpenerhaving a frame including a crossmember bracketing the sides and end of agrinding element, and forming an opening through which said grindingelement extends, for machining the cutter gauge of a saw chain link, theattachment comprising:

a plate removably mounted over said frame crossmember opening and havinga flat portion with an opening formed therein through which a portion ofthe grinding element extends,

the ends of said plate being formed to engage the frame of said grinderin an adjustable spaced relation in order to change the amount ofgrinding element which extends through said flat portion openmg, saidplate ends including edge portions, one of said edge portions includinga pair of tabs extending substantially perpendicularly from said platefor engaging a pair of holes formed in the crossmember, and the otheredge portion including a folded over end portion means extending fromsaid plate for hooking onto the frame of the chain saw sharpener andthereby fixing said plate to said sharpener at a predetermined distancefrom said crossmember when said tabs are fitted into the holes of saidcrossmember, and a-guard formed by a portion adjacent the flat portionopening extending substantially perpendicularly from said plate in thedirection opposite from said end edge portions, whereby, where said flatportion is placed on a saw chain bridging two links during grinding ofthe top of the cutter gauge of one of said links, said guard will extendinto an opening in said link between said grinding element and thecutting edge of the link being ground to prevent the grinding elementfrom hitting said cutting edge.

, 6; The depth gauge attachment of claim 5 wherein said cross memberincludes an adjustment means for changing the spacing of said depthgauge attachment with respect to the frame of said sharpener to in turnchange the amount the grinding element extends through the opening ofsaid plate.

7. The depth gauge attachment of claim 6 wherein said adjustment meansincludes a pivotable plate secured to said frame which can be adjustablypivoted outwardly from said frame between said frame and said plate tohold said plate away from said frame.

8. The depth gauge attachment of claim 5 wherein said folded over endportion forms an edge angled with respect to said grinding elementwhereby as said grinder is moved perpendicularly to the depth gaugeportion being machined with said tapered portion coacting with a fixedsurface said depth gauge attachment and grinder will be caused to movelongitudinally across the top of the cutter gauge being ground.

1. A depth gauge attachment for use with a motorized saw chain sharpenerhaving a grinding element for machining the cutter gauge of a saw chainlink, the attachment comprising: a plate removably secured to saidsharpener and including a flat portion having an opening formed thereinthrough which a portion of the grinding element extends, a guard formedby a portion extending substantially perpendicularly from said plateadjacent said opening, whereby, when said flat portion of said plate isplaced on a saw chain bridging two links, said grinding element willengage the top surface of the cutter gauge of one of said links to apredetermined depth and said guard will extend into an opening in saidlink between said grinding element and the cutting edge of the linkbeing ground to prevent the grinding element from hitting said cuttingedge.
 2. The depth gauge attachment of claim 1 wherein said plate isadjustable with respect to said saw chain sharpener to change the amountof grinding element which extends through said opening.
 3. The depthgauge attachment of claim 2 wherein said plate includes a stud fixed toone side thereof for securing said attachment to the sharpener, and saidsaw chain sharpener includes adjustable means to change the amount ofgrinding element which extends through said opening.
 4. The depth gaugeattachment of claim 2 wherein said saw chain sharpener includes a framehaving a cross member bracketing the sides and end of the grindingelement and forming an opening through which the grinding elementextends and over which said plate is mounted, said plate includingupturned edge portions extending in the direction opposite from saidplate than said guard portion and engaging said cross member in such amanner that said attachment is spaced a predetermined distance from saidcross member.
 5. A depth gauge attachment for use with a motorized sawchain sharpener having a frame including a crossmember bracketing thesides and end of a grinding element, and forming an opening throughwhich said grinding element extends, for machining the cutter gauge of asaw chain link, the attachment comprising: a plate removably mountedover said frame crossmember opening and having a flat portion with anopening formed therein through which a portion of the grinding elementextends, the ends of said plate being formed to engage the frame of saidgrinder in an adjustable spaced relation in order to change the amountof grinding element which extends through said flat portion opening,said plate ends including edge portions, one of said edge portionsincluding a pair of tabs extending substantially perpendicularly fromsaid plate for engaging a pair of holes formed in the crossmember, andthe other edge portion including a folded over end portion meansextending from said plate for hooking onto the frame of the chain sawsharpener and thereby fixing said plate to said sharpener at apredetermined distance from said crossmember when said tabs are fittedinto the holes of said crossmember, and a guard formed by a portionadjacent the flat portion opening extending substantiallyperpendicularly from said plate in the direction opposite from said endedge portions, whereby, where said flat portion is placed on a saw chainbridging two links during grinding of the top of the cutter gauge of oneof said links, said guard will extend into an opening in said linkbetween said grinding element and the cutting edge of the link beingground to prevent the grinding element from hitting said cutting edge.6. The depth gauge attachment of claim 5 wherein said cross memberincludes an adjustment means for changing the spacing of said depthgauge attachment with respect to the frame of said sharpener to in turnchange the amount the grinding element extends through the opening ofsaid plate.
 7. The depth gauge attachment of claim 6 wherein saidadjustment means includes a pivotable plate secured to said frame whichcan be adjustably pivoted outwardly from said frame between said frameand said plate to hold said plate away from said frame.
 8. The depthgauge attachment of claim 5 wherein said folded over end portion formsan edge angled with respect to said grinding element whereby as saidgrinder is moved perpendicularly to the depth gauge portion beingmachined with said tapered portion coacting with a fixed surface saiddepth gauge attachment and grinder will be caused to move longitudinallyacross the top of the cutter gauge being ground.